Is standard for Listeria?

During the past six years, new species of the genus Listeria have been isolated from foods and other environmental niches worldwide. The Standard method EN ISO 11290-1 that is currently under revision will include in its scope all Listeria species in addition to L. monocytogenes.

What is Listeria enumeration?

Standards for Detection and Enumeration of Listeria monocytogenes and Listeria spp. in the food chain. In Part 1, a horizontal method for the detection of Listeria monocytogenes and Listeria spp. is specified, and in Part 2, the enumeration of these organisms in food, animal feed and environmental samples is described.

How does Listeria Chromogenic Agar work?

A Listeria chromogenic isolation medium is used that results in the formation of blue-green colonies by Listeria species due to the β-glucosidase activity of these bacteria. ivanovii but not other Listeria species to produce an opaque halo around the colony.

Which is the ISO standard method for Listeria detection?

Agar Listeria according to Ottaviani and Agosti (LOA agar), a chromogenic selective agar, which distinguishes L. monocytogenes and L. ivanovii from other species of Listeria, was adopted in 2004 by the International Organization for Standardization (ISO) as the standard medium for the detection of L. monocytogenes.

How long do you incubate agar Listeria plates?

Incubate at 37°C and read plates after 24 to 48 hours. It is not necessary to prolong incubation to 48 hours for the plates screened at 24 hours what ever the result of the screening. •Enumeration ofL i st er a m o ncy g according to ALOA COUNT™

When to put Listeria ivanoviican in the refrigerator?

After 48 hours of incubation, Listeria ivanoviican show the same characteristics as Listeria monocytogenes. Under the two circumstances, carrying out confirmation tests allow to differentiate the two species without hesitation. ALOA plates can be placed in the refrigerator after incubation.

How is principle Aloa used to detect Listeria?

PRINCIPLE ALOA™ is a selective medium used for the detection and enumeration of L .monocytogenesin foodstuffs samples (AFNOR VALIDATION certified methods – see enclosed protocols). This medium is also used to carry out screening and enumeration of L.monocytogenes& L.spin foodstuffs and any kind of samples (ISO 11290 standard protocols).